The Court however postponed the trial to August 28.
The Criminal Court approved combining the cases against Mr Abhisit and Phra Suthep (Mr Suthep, who is now in the Buddhist monkhood), former director of the Centre for Resolution of the Emergency Situation (CRES) during the Abhisit administration, because both cases share the same set of witnesses and evidence.
The court will resume its examination of evidence and witnesses on August 28.
Mr Abhisit and Phra Suthep arrived at the Criminal Court on Ratchadaphisek Road in Bangkok this morning as the court checked their accounts, evidence and witnesses.
The public prosecution charged them with ordering and attempting the murders of others in relation to fatal crackdowns on red shirt protesters in 2010.
After listening to the charges, Phra Suthep denied them all.
Mr Abhisit and Phra Suthep asked the court to decide if the Department of Special Investigation had authority to investigate their cases because they were accused of malfeasance.
Their argument caused the court to postpone the examination of evidence and witnesses to 9am on August 28.
Phra Suthep said he felt at peace and did not plan to leave the monkhood yet.